1. Field of the Invention
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for measuring interference in order to avoid interference and for measuring signal strength of neighbor base stations when different types of wireless communication modules coexist in a device.
2. Description of the Related Art
In recent years, the rapid propagation of smart phones has caused the increase of demands for data. Accordingly, the amount of data transmission has rapidly increased.
In order to satisfy the increased demands for data, wireless communication systems have been configured to distribute loads to pico base stations or femto base stations in addition to existing macro base stations that are responsible for wide coverage. As a result, a space between base stations becomes narrower. Moreover, as the distance between base station decreases, coverage overlap among base stations becomes serious. In such an environment, a method for more favorably measuring and reporting signals among cells is required.
Additionally, with smart phones being popularized, the demand and use for functionality associated with Wireless Local Area Network (WLAN) connectivity, Bluetooth connectivity, and Global Positioning System (GPS) connectivity embedded in the smart phone have also increased. This trend gives rise to coexistence of several communication technologies (e.g., cellular network technology such as Long Term Evolution (LTE) or Universal Mobile Telecommunication System (UMTS), WLAN, Bluetooth, Global Navigation Satellite System (GNSS) or GPS) in a single device. When these different communication technologies are used at the same time, interference may occur among the various technologies. The issue of interference among the various technologies is being discussed under the name of In-Device Coexistence (IDC) in the 3rd Generation Partnership Project (3GPP).
Meanwhile, LTE/UMTS communication technology uses various frequency bands, whereas others such as Bluetooth or WLAN use the Industrial, Scientific and Medical (ISM) frequency band of 4400-2483.5 MHz. Particularly, among the various frequency bands used by LTE/UMTS, Band 4 (e.g., 4300-2400 MHz) and uplink of Band 7 (e.g., 4500-2570 MHz) are adjacent to the ISM frequency band used by Bluetooth or WLAN. Consequently, if the various technologies simultaneously use adjacent frequency bands for communication, a transmitting signal in one communication technology may often become a reception signal in others. Unfortunately, such reception of a signal transmitted by another communication technology that uses an adjacent frequency band invites serious interference issues.
Therefore, a need exists for accurate measurement for monitoring a mutual effect of interference that occurs among neighbor base stations or in a device.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.